Damper Application Guide 1.” 1 Common 2 2 + Hot
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Airflow Simulations Around OA Intake Louver with Electronic Velocity
Airflow Simulations around OA Intake Louver with Electronic Velocity Sensors Hwataik Han*1, Douglas P. Sullivan2 and William J. Fisk3 1 Professor, Kookmin University, Korea 2 Research Associate, Indoor Environment Department, Lawrence Berkeley National Laboratory, USA 3 Director, Indoor Environment Department, Lawrence Berkeley National Laboratory, USA Abstract It is important to control outdoor airflow rates into HVAC systems in terms of energy conservation and healthy indoor environment. Technologies are being developed to measure outdoor air (OA) flow rates through OA intake louvers on a real time basis. The purpose of this paper is to investigate the airflow characteristics through an OA intake louver numerically in order to provide suggestions for sensor installations. Airflow patterns are simulated with and without electronic air velocity sensors within cylindrical probes installed between louver blades or at the downstream face of the louver. Numerical results show quite good agreements with experimental data, and provide insights regarding measurement system design. The simulations indicate that velocity profiles are more spatially uniform at the louver outlet relative to between louver blades, that pressure drops imposed by the sensor bars are smaller with sensor bars at the louver outlet, and that placement of the sensor bars between louver blades substantially increases air velocities inside the louver. These findings suggest there is an advantage to placing the sensor bars at the louver outlet face. Keywords: ventilation; outdoor -
Theoretical Study of the Flow in a Fluid Damper Containing High Viscosity
Theoretical study of the flow in a fluid damper containing high viscosity silicone oil: effects of shear-thinning and viscoelasticity Alexandros Syrakosa,∗, Yannis Dimakopoulosa, John Tsamopoulosa aLaboratory of Fluid Mechanics and Rheology, Department of Chemical Engineering, University of Patras, 26500 Patras, Greece Abstract The flow inside a fluid damper where a piston reciprocates sinusoidally inside an outer casing containing high-viscosity silicone oil is simulated using a Finite Volume method, at various excitation frequencies. The oil is modelled by the Carreau-Yasuda (CY) and Phan-Thien & Tanner (PTT) constitutive equations. Both models account for shear-thinning but only the PTT model accounts for elasticity. The CY and other gener- alised Newtonian models have been previously used in theoretical studies of fluid dampers, but the present study is the first to perform full two-dimensional (axisymmetric) simulations employing a viscoelastic con- stitutive equation. It is found that the CY and PTT predictions are similar when the excitation frequency is low, but at medium and higher frequencies the CY model fails to describe important phenomena that are predicted by the PTT model and observed in experimental studies found in the literature, such as the hysteresis of the force-displacement and force-velocity loops. Elastic effects are quantified by applying a decomposition of the damper force into elastic and viscous components, inspired from LAOS (Large Am- plitude Oscillatory Shear) theory. The CY model also overestimates the damper force relative to the PTT, because it underpredicts the flow development length inside the piston-cylinder gap. It is thus concluded that (a) fluid elasticity must be accounted for and (b) theoretical approaches that rely on the assumption of one-dimensional flow in the piston-cylinder gap are of limited accuracy, even if they account for fluid viscoelasticity. -
Geometry of Thermodynamic Processes
Article Geometry of Thermodynamic Processes Arjan van der Schaft 1, and Bernhard Maschke 2 1 Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, Jan C. Willems Center for Systems and Control, University of Groningen, the Netherlands; [email protected] 2 Univ. Lyon 1, Université Claude Bernard Lyon 1, CNRS, LAGEP UMR 5007, Villeurbanne, France; [email protected] * Correspondence: [email protected]; Tel.: +31-50-3633731 Received: date; Accepted: date; Published: date Abstract: Since the 1970s contact geometry has been recognized as an appropriate framework for the geometric formulation of the state properties of thermodynamic systems, without, however, addressing the formulation of non-equilibrium thermodynamic processes. In [3] it was shown how the symplectization of contact manifolds provides a new vantage point; enabling, among others, to switch between the energy and entropy representations of a thermodynamic system. In the present paper this is continued towards the global geometric definition of a degenerate Riemannian metric on the homogeneous Lagrangian submanifold describing the state properties, which is overarching the locally defined metrics of Weinhold and Ruppeiner. Next, a geometric formulation is given of non-equilibrium thermodynamic processes, in terms of Hamiltonian dynamics defined by Hamiltonian functions that are homogeneous of degree one in the co-extensive variables and zero on the homogeneous Lagrangian submanifold. The correspondence between objects in contact geometry and their homogeneous counterparts in symplectic geometry, as already largely present in the literature [2,18], appears to be elegant and effective. This culminates in the definition of port-thermodynamic systems, and the formulation of interconnection ports. -
Performance Measurements of a Unique Louver
Performance Measurements Grant O. Musgrove Southwest Research Institute, of a Unique Louver Particle San Antonio, TX 78238 e-mail: [email protected] Separator for Gas Turbine Engines Karen A. Thole Mechanical and Nuclear Engineering Department, Solid particles, such as sand, ingested into gas turbine engines, reduce the coolant flow The Pennsylvania State University, in the turbine by blocking cooling channels in the secondary flow path. One method to University Park, PA 16802 remove solid particles from the secondary flow path is to use an inertial particle separa- tor because of its ability to incur minimal pressure losses in high flow rate applications. In this paper, an inertial separator is presented that is made up of an array of louvers Eric Grover followed by a static collector. The performance of two inertial separator configurations was measured in a unique test facility. Performance measurements included pressure Joseph Barker loss and collection efficiency for a range of Reynolds numbers and sand sizes. To comple- ment the measurements, both two-dimensional and three-dimensional computational United Technologies Corporation – results are presented for comparison. Computational predictions of pressure loss agreed Pratt & Whitney, with measurements at high Reynolds numbers, whereas predictions of sand collection East Hartford, CT 06108 efficiency for a sand size range 0–200lm agreed within 10% of experimental measure- ments over the range of Reynolds numbers. Collection efficiency values were measured to be as high as 35%, and pressure loss measurements were equivalent to less than 1% pres- sure loss in an engine application. [DOI: 10.1115/1.4007568] Introduction operating principle of inertial separators is to cause the particle- laden flow to abruptly change trajectory, whereby the particles do Aircraft gas turbines ingest solid particles during takeoff, land- not react to the change in flow direction due to their larger inertia ing, and while flying in dusty environments. -
179 Design of a Hydraulic Damper for Heavy Machinery
ANALELE UNIVERSIT ĂłII “EFTIMIE MURGU” RE ŞIłA ANUL XVIII, NR. 1, 2011, ISSN 1453 - 7397 Emil Zaev, Gerhard Rath, Hubert Kargl Design of a Hydraulic Damper for Heavy Machinery A hydraulic unit consisting of an accumulator as energy storage element and an orifice providing friction was designed to damp oscillations of a machine during operation. In the first step, a model for the gas spring was developed from the ideal gas laws for the dimensioning the elements. To model the gas process with a graphical simulation tool it is necessary to find a form of the gas law which can be integrated with a numerical solver, such as Tustin, Runge-Kutta, or other. For simulating the working condition, the model was refined using the van der Waals equations for real gas. A unified model representation was found to be applied for any arbitrary state change. Verifications were made with the help of special state changes, adiabatic and isothermal. After determining the dimensional parameters, which are the accumulator capacity and the orifice size, the operational and the limiting parameters were to be found. The working process of a damper includes the gas pre-charging to a predefined pressure, the nearly isothermal static loading process, and the adiabatic change during the dynamic operation. Keywords : Vibration damping, hydraulic damping, gas laws 1. Introduction Mining Machines, like the ALPINE Miner of the Sandvik company in Fig. 1, are subject to severe vibrations during their operation. Measures for damping are re- quired. Goal of this project was to investigate the potential of damping oscillation using the hydraulic cylinders of the support jacks (Fig. -
High Performance House Best Practices Guide
New York State Energy Research & Development Authority High Performance House Best Practices Guide Design Intelligence for Energy Performance in Single Family Homes TABLE OF CON T EN T S High Performance House 1.1 Initial Work................................... 3 1.2 Process.......................................... 4 1.3 Testing........................................... 4 1.3.1 Building Construction.............................. 4 1.3.2 Building Form and Siting......................... 5 1.3.3 Passive Sustainable Strategies................ 6 1.3.4 Active Sustainable Strategies................... 14 1.4 Conclusions................................... 14 1.4.1 Additional Recommendations.................. 15 2 1.1 INitiAL WORK 1.1 Initial Work ON cti Preliminary analysis looked purely at geometric implications on energy use. This theoretical investigation tested a variety of building forms and found two general guidelines that govern performance. Across all building manipulations, results showed that forms minimizing volume and RODU T maximizing southern exposure perform best. This lines with rational thought; increased volume N increases the volume of required conditioned space, while maximizing southern exposure allows I for greatest winter solar gains and daylighting. Following this study, energy analysis was given for three, previously conceived housing designs – “Slope House”, “Underground House” and “X House”. In all cases, formal design (siting, building form, orientation) were given, fixed parameters. This proved a challenge to the energy optimization of the house. For the “Slope House”, building volume opens to the west without the benefit of southern expo- sure on the open face. Passive solar gains were minimal, with excessive shading on south facing windows. The majority of glazing is to the north, which effectively cuts the building’s thermal resistance/storage without the offsetting solar gains received on southern exposures. -
Don't Let Dollars Disappear up Your Chimney!
ENERGY SAVINGTIPS DON’T LET DOLLARS DISAPPEAR UP YOUR CHIMNEY! You wouldn’t leave a window wide open in cold weather. Having a fireplace with an open flue damper is the same as having a window open. That sends precious winter heat and money right up the chimney! Here’s how you can heat your home, and not the neighborhood! KEEP THE FIREPLACE DAMPER CLOSED WHEN THE FIREPLACE IS NOT BEING USED The damper is a flap inside the chimney or flue. It has an open and a closed position. When a fire is burning, the damper should be in the open position to allow smoke to escape up the fireplace flue and out the chimney. When you’re not using the fireplace, the damper should be closed. If you can’t see the handle or chain that opens and closes the damper, use a flashlight and look up inside the chimney flue. The handle could be a lever that moves side to side or back and forth. If a chain operates the damper, you may have to pull both sides to determine which one closes or opens the damper. KEEP YOUR HEAT IN YOUR HOME! Even the most energy efficient homes can fall victim to fireplace air leaks. Your fireplace may be reserved for a handful of special occasions or especially cold nights. When it’s not in use, though, your home loses heat – and costs you money – without you knowing it. Using the heat from your fireplace on a cold winter night may be cozy, but that fire is a very inefficient way to warm up the room. -
System Controls Engineering Guide
SECTION G Engineering Guide System Controls System Controls Engineering Guide Introduction to VAV Terminal Units The control of air temperature in a space requires that the loads in the space are offset by some means. Space loads can consist of exterior loads and/or interior loads. Interior loads can consist of people, mechanical equipment, lighting, com puters, etc. In an 'air' conditioning system compensating for the loads is achieved by introducing air into the space at a given temperature and quantity. Since space loads are always fluctuating the compensation to offset the loads must also be changing in a corresponding manner. Varying the air temperature or varying the air volume or a combination of both in a controlled manner will offset the space load as required. The variable air volume terminal unit or VAV box allows us to vary the air volume into a room and in certain cases also lets us vary the air temperature into a room. YSTEM CONTROLS YSTEM S The VAV terminal unit may be pressure dependent or pressure independent. This is a function of the control package. ENGINEERING GUIDE - Pressure Dependent A device is said to be pressure dependent when the flow rate passing through it varies as the system inlet pressure fluctuates. The flow rate is dependent only on the inlet pressure and the damper position of the terminal unit. The pressure dependent terminal unit consists of a damper and a damper actuator controlled directly by a room thermostat. The damper is modulated in response to room temperature only. Since the air volume varies with inlet pressure, the room may experience temperature swings until the thermostat repositions the damper. -
Life Safety Dampers Selection and Application Manual • Ceiling Radiation Dampers • Fire Dampers • Combination Fire Smoke Dampers • Smoke Dampers
Life Safety Dampers Selection and Application Manual • Ceiling Radiation Dampers • Fire Dampers • Combination Fire Smoke Dampers • Smoke Dampers August 2016 1 Table of Contents HOW TO USE THIS MANUAL DAMPER APPLICATION 3 • Fire Damper Application • Smoke Damper Application • Combination Fire Smoke Damper Application • Corridor Ceiling Combination Fire Smoke Damper Application DAMPER SELECTION 5 • Selection Process • Key Points to Remember ACTUATOR SELECTION 7 • Selection Process • Actuator Mounting Options • Key Points to Remember SLEEVE REQUIREMENTS 9 • Sleeve Thickness • Sleeve Length • Key Points to Remember SPACE REQUIREMENTS FOR PROPER INSTALLATION 10 • Key Points to Remember DAMPER OPTIONS 11 • Control Options • Security Bar Options • Transition Options • Key Points to Remember INSTALLATION REQUIREMENTS 15 • Combination Fire Smoke Damper Installation • Smoke Damper Installation • Actuator Installation • Damper and Actuator Maintenance • Key Points to Remember SPECIAL INSTALLATION CASES 17 • Maximum Damper Size Limitations • Horizontal Fire Smoke Damper in a Non-Concrete Barrier • AMCA Mullion System • What if a Damper Cannot be Installed per the Manufacturer’s Installation Instructions? • What if a Damper Cannot be Installed in the Wall? • Steps to Take When an Unapproved Installation Must be Provided CEILING RADIATION DAMPERS 20 • Ceiling Radiation Damper Application • Key Points to Remember CODES AND STANDARDS 21 • Compliance with the Applicable Building Codes • The National Fire Protection Association • Code and Standard Making -
Damper & Shutter Accessory Brochure
DAMPER & SHUTTER ACCESSORIES | Product Guide 1 DAMPER & SHUTTER ACCESSORIES Benefits and Features Benefits Dampers and shutters are used to prevent undesirable Flange backdrafts into a building or to control airflow through a The flange adds stiffness and Actuators system. When mounted in a wall application shutters can limit provides a location for installation Sometimes referred to as the amount of precipitation that enters a building. fasteners. “motorpacks”. They motorize the damper operation and typically Large Units power the damper open or Large size units may Blade shutter open. Used in low require the use of The damper blades are the moving airflow applications or in multiple panels. These parts of a damper / shutter. Blades installation where damper panels can be shipped are attached to an axle. Axle are control is desired. The addition either mechanically located at either the edge or center of a transformer may be fastened together or of the blades. required to meet the specified shipped loose for field voltage. See page 23 for assembly. Frame additional details. Motorized The frame is the structure of Blade Seal For motorized large the damper and shutter. When Attached to the edge of the single panel and installed, the frame must be blade and limits air leakage. multiple panel units square and true and not may require the use of ‘racked’ for proper operation. Linkage multiple motorpacks or (Not shown) actuators to operate. Jamb Seal Links the blades together to Submittals Low leakage dampers may have operation in unison. Also Consult submittal this additional construction feature. connects the blades to the drawing for number of The jam seal reduces the gap actuator. -
IAQ Economizer LOGIC BOX
IAQ Economizer LOGIC BOX Split-system Economizing/Indoor Air Quality/CO Alarm Activated Works on forced air systems, with or without air conditioning installed Enables cost saving cooling strategy: Expensive mechanical cooling can be set at a higher temperature Fresh Air Cooling can be set at a lower temperature Supports a variety Indoor Air Quality configurations: Continuous introduction Timed introduction CO2 or VOC sensor activated introduction Provides alarm activated fresh air introduction supporting CO or other alarm installations Occupant interface provides easy override, along with readiness, damper and fault status, (continuous fault detection) Operational tests can be conducted from within the conditioned space Quick connect wiring harnesses provide fast, correct termination FRESH AIR MANUFACTURING CO. FAMCO IAQ Economizer Famcoiaq.com 649 N. Ralstin St., Meridian, ID 83642 * (208)884-8931 * (800)-234-1903 * FAX: (208)884-8943 IAQ Economizer ECONOMIZER SYSTEM Damper Actuator Exhaust Damper Transformer Thermostat Logic Literature Box Cables Damper Box Actuator – Honeywell MS8105A1030, 24 VAC, 44 lb-in torque Outdoor thermostat- Dayton RLZ94A Nema 4X, Range 30º-110º F Transformer – RIB Functional Devices, Inc. TR50VA005 , 50VA All required System Cables are provided: • Power 40’ • Furnace 40’, plenum rated, HVAC industry standard color coding for furnace board termination • Damper Box 50’, plenum rated • Outdoor thermostat, 70’ , shielded, non polarity sensitive FRESH AIR MANUFACTURING CO. FAMCO IAQ Economizer -
HVAC Control & Balancing Dampers
HVAC Control & Balancing Dampers Models VCD, ICD, FBH, FBV, MBD and RBD • Selection • Construction • Performance January1 2018 Design and Construction Features ® Commercial Control Dampers are used in Blade buildings to regulate the flow of air in an Bearing HVAC system. They can be used in intake, exhaust, or mixed air applications. There are two categories of control Shaft Extension dampers: Jamb Seal • Balancing • Volume Control Standoff Bracket Axle Frame Blade Seal Linkage Frame - Tog-L-Loc® Advantage Greenheck control dampers utilize a 5 in. x 1 in. (127mm x 25mm) hat channel frame. Each frame is built with four separate pieces of material and joined by our Tog-L-Loc® process. Rigid frame - The joint has an equivalent thickness of 10 ga. (3.5mm) steel. Increased corrosion resistance - The Tog-L-Loc process does not use heat, so Greenheck damper frames have greater corrosion resistance by retaining the galvanized coating. Square frame for easier install - Using four separate frame components (top, bottom, and two sides), Greenheck’s Tog-L-Loc process results in four sturdy, Tog-L-Loc® 90º joints. This ensures that each Greenheck damper is square and provides Reinforced Corner optimum performance in the field. Frame Options There are five frame options available: • Channel (standard) - allows damper to be insert mounted into an opening or duct • Single flange or single reverse flange - can be insert mounted or directly mounted to the wall or mating surfaces such as a Channel Single Single Double Quick plenum wall Frame Flange Reverse Flange Connect (actuator side) Flange • Double flange - when you are not sure (opposite actuator) which side you need a flange • Quick connect (VCD-43, -43V; ICD series) - designed to match up to a TDC, TDF, or Ductmate connection Maximize Performance - Low Profile Frame On dampers that are 17 in.